Refrigerated cabinet

ABSTRACT

A refrigerated cabinet includes a fan assisted refrigeration unit and a duct in communication with the fan, for distributing cold air from the fan throughout the cabinet; the duct is substantially the full width and the full length of the product storage of the cabinet and at least a major portion of the duct has a substantially constant width; one end of the duct is in communication with a fan and the opposite end of the duct provides an end outlet; intermediate outlets are formed through the duct between the ends, to supply air from the duct to the product storage portion of the cabinet; the size of the end outlet is substantially smaller than the size of the intermediate outlets, so that in use the duct is pressurized compared to the remainder of the cabinet.

TECHNICAL FIELD

The present invention relates to an improvement in a refrigeratedcabinet of the type in which cold air is circulated around the cabinetby a fan.

BACKGROUND ART

For efficient refrigerated storage of product within the cabinet, it isimportant that cold air from the refrigeration unit is circulated evenlythroughout the cabinet. In known designs, the evaporator of therefrigeration unit is fitted with one or more fans, which are driven tocirculate cold air from the vicinity of the refrigeration unitthroughout the body of the cabinet. However, air naturally tends towardsthe path of least resistance, and if the shelves of the cabinet areheavily stacked with product, restricting the spaces between adjacentshelves, air tends to move preferentially towards the opposite end ofthe cabinet from the fan, rather than between the shelves.

DISCLOSURE OF INVENTION

It is therefore an object of the present invention to provide arefrigerated cabinet in which the above described problem is overcome orat least ameliorated.

A refrigerated cabinet which includes a fan assisted refrigeration unitand a duct in communication with said fan, said duct being adapted todistribute cold air from said fan throughout said cabinet;

wherein said duct extends substantially the full width and the fulllength of the product storage portion of the cabinet and at least amajor portion of said duct has a substantially constant width; one endof said duct being in communication with the fan and the opposite end ofsaid duct providing an end outlet; the portion of said duct between saidends being formed with a plurality of intermediate outlets adapted tosupply air from said duct to the product storage portion of the cabinet;the size of said end outlet being substantially smaller than the size ofsaid intermediate outlets, such that in use air in said duct ispressurized compared to the remainder of said cabinet.

The end outlet may be formed in any suitable manner, e.g. by forming anaperture through the duct at or adjacent the end of the duct or byforming a flange which extends across part of the width of the duct andso forms an end outlet of reduced size.

The fan assisted refrigeration unit may be mounted at any of a varietyof positions on the cabinet, e.g. at the top of the cabinet or at thebase of the cabinet or at one of the ends of the cabinet.

The degree of pressurization of the air in the duct compared to theremainder of the cabinet can be varied to suit the size and shape of thecabinet and the degree of refrigeration required. Typically, a pressureincrease in the duct of about 60% compared to the remainder of thecabinet for a refrigerated cabinet which has a top mounted fan assistedrefrigeration unit, is found to give good results in practice.

BRIEF DESCRIPTION OF DRAWINGS

By way of example only, preferred embodiments of the present inventionare described in detail, with reference to the accompanying drawings, inwhich:

FIG. 1 shows a diagrammatic longitudinal section through a cabinet inaccordance with a first embodiment of the invention;

FIG. 2 shows a diagrammatic longitudinal section through a cabinet inaccordance with a second embodiment of the invention; and

FIG. 3 shows a diagrammatic longitudinal section through a cabinet inaccordance with a third embodiment of the invention.

Referring to FIG. 1, a refrigerated cabinet 2 is of known type:- aninsulated cabinet with a full height glazed door 3 and a top mountedrefrigeration unit 4. The cabinet 2 is mounted on castors 5. Theinterior of the cabinet is provided with racks or shelves 6 on whichproduct 7 is displayed.

The refrigeration unit 4 is of conventional type, and fitted with an aircirculation fan 8 powered by a fan motor in known manner. On leaving thefan 8, the cold air (arrows A) passes down a duct 10 formed down theback of the cabinet, and extending across the full width of the back ofthe cabinet.

To keep the product 7 chilled efficiently, it is important that the coldair is circulated evenly around the interior of the cabinet. However, inknown designs of cabinet, the path of least resistance for the cold airis to pass directly down the duct 10 to the bottom of the cabinet; thisis especially so when the cabinet contains a large volume of product andthe space between adjacent shelves 6 is restricted. It will beappreciated that this leads to inefficient chilling of the product.

To overcome this problem, the width of the duct 10 is restricted by aflange 11 which extends across the full width of the back of the cabinetand leaves only a small space between the outer end of the flange 11 andthe rear wall 13 of the cabinet as the end outlet 12. The effect of thisrestriction is to make it more difficult for air to enter the bottomspace 14 below the lowest shelf in the cabinet and thus to pressurizethe air in the duct. This pressurization of the duct 10 forces air outthrough intermediate outlets 15,15 a:- slots 15 formed across the duct10 immediately below each of the cabinet shelves 6, (as indicated byArrows B) and smaller slots 15 a positioned between the slots 15; thisgives a greatly improved distribution of air throughout the whole lengthof the cabinet.

The intermediate outlets 15,15 a may be of any length, but typically areformed as a series of short slots across the width of the duct, oflarger size than the end outlet 12.

The second and third embodiment as shown in FIGS. 2 and 3 are of thesame general type of design as that of FIG. 1 and similar parts aregiven the same reference numerals.

In the embodiment of FIG. 2, the refrigeration unit 4 is mounted at thebottom of the cabinet, so that cold air (Arrow A) passes upwards fromthe bottom of the cabinet along the duct 10. The end outlet 12 a isformed as a small aperture in the wall of the duct 10. In thisembodiment, the width of the duct 10 remains constant adjacent the endoutlet 12 a, (i.e. there is no equivalent to flange 11, FIG. 1). Thefact that the end outlet 12 a is small compared to the intermediateoutlets 15,15 a has the effect of pressuring the air in the duct 10.

In the embodiment of FIG. 3, the refrigerated cabinet 2 is horizontaland the access door (not visible) is a hinged or sliding panel acrossthe front of the cabinet. The refrigeration unit 4 is mounted at one endof the cabinet and the duct 10 is formed along the top of the cabinet.As in the FIG. 2 embodiment, the end outlet 12 b of the duct is formedas a small aperture in the wall of the duct.

In FIGS. 2 and 3, the cold air coming from the refrigeration unit isindicated by Arrow A and the air circulating through the food storagearea by Arrows B.

1. A refrigerated cabinet which includes a fan assisted refrigerationunit and a duct in communication with said fan, said duct being adaptedto distribute cold air from said fan throughout said cabinet; whereinsaid duct extends substantially the full width and the full length ofthe product storage portion of the cabinet and at least a major portionof said duct has a substantially constant width; one end of said ductbeing in communication with the fan and the opposite end of said ductproviding an end outlet; the portion of said duct between said endsbeing formed with a plurality of intermediate outlets adapted to supplyair from said duct to the product storage portion of the cabinet; thesize of said end outlet being substantially smaller than the size ofsaid intermediate outlets, such that in use air in said duct ispressurized compared to the remainder of said cabinet.
 2. The cabinet asclaimed in claim 1, wherein said end outlet is formed by an aperturethrough the duct at or adjacent the end of the duct.
 3. The cabinet asclaimed in claim 1, wherein said end outlet is formed by a flangeextending across part of the width of said duct.
 4. The cabinet asclaimed in any one of the preceding claims, wherein said fan assistedrefrigeration unit is mounted at the top of the cabinet.
 5. The cabinetas claimed in any one of claims 1-3, wherein said fan assistedrefrigeration unit is mounted at the base of the cabinet.
 6. The cabinetas claimed in any one of claims 1-3, wherein a fan assistedrefrigeration unit is mounted at one end of the cabinet.